greenlab, have you got any thing working yet? Im no expert, but i recon it would be possible to control a parrallel port printer from your arduino, as at the end of the day, the parrel port uses the same voltages. And im sure, at the most basic, you can send ascci charictors! Youve got me interested, im going to look in to it. I'll let you know what i find.

Printing from an Arduino would be a great way to implement a simple data logger for some applications.

The printer would want to be an "old fasioned" line- by- line printer.

If the data were subsequently wanted in machine readable form, modern OCR should be able to do the conversion easily enough.

If the number of pins required to drive the printer would be a problem, then the main Arduino could send "please print this" messages over just two pins (not the valuable serial comms pins) to a second dedicated Arduino (or ad hoc PIC), and THAT could drive the printer. That "answer" would be very similar, just working in the opposite direction, to what I've got working at prototype level for taking the overheads of reading a keyboard off of my "client" Arduino.

I used to have a bunch of serial printers. I threw them out ages ago (look up Digital Decwriter II and III to see what I had, a few of those took up a ton of space). You can probably find old dot-matrix serial printers and computer junk stores.

If you can find a serial to parallel adapter like this one http://www.blackbox.co.uk/technical/manuals/P/PI125A.pdfit would work for data logging if your parallel printer supported a simple ASCII text protocol